Driving speed and fuel consumption Exercise $9$ (page $159$) gives data on the fuel consumption y

of a car at various speeds x. Fuel consumption is measured in liters of gasoline per $100$ kilometers

driven and speed is measured in kilometers per hour. A statistical software package gives the least-squares regression line and the residual plot shown below. The regression line is $yˆ=11.058-$ $0.01466x$ Would it be appropriate to use the regression line to predict $y$ from $x$? Justify your answer.

The regression line is $\stackrel{⏜}{y}=11.058-0.01466x$

A regression line is a straight line that depicts the change in a response variable $y$ when an explanatory variable$x$ changes. By putting this $x$ into the equation of the line, you may use a regression line to predict the value of $y$ for any value of $x$

The shown residual graphic effectively horizontalizes the regression line. It amplifies the points' deviations from the line; if the regression line reflects the main pattern of the data, the residuals should be devoid of pattern. A residual plot with a visible curved pattern is shown in the image. For these data, a straight line is not an effective model. As a result, using the regression line to predict $Y$from $X$ would be inappropriate.